Python opening a file and turning it into a list

Question

I am trying to open a file and then take that file and turn it into a list I'm kinda lost as to how to get it into a list i know I can open a file with open() I don't want to use the read.line either

Input (build1,200),(build2,267) all in a txt file that needs to be opened

Output

Build1,200

Build2,200

Every time I try to add the info to a list it just adds the first one then it stops .

You need to specify what you mean by list. Is a certain line split in order to create a list? Or do you mean the physical lines of the file? — Malik Brahimi, Mar 09 '15 at 21:18
What format is the data in the file? What format would you expect it to look like when you've loaded it? Without knowing that people can't give you help reading it. — Will, Mar 09 '15 at 21:23
Ok the data is going to be a word followed by a distance Like this ( tomato 234) there are a couple hundred of these in the file I've got to calculate the distances of them so I need all of that information out into a list so I can do that — Andrew3943, Mar 09 '15 at 21:25
After I do this I'm going to use an insertion sort to sort it and then I'm going to get the median with another function — Andrew3943, Mar 09 '15 at 21:32
sounds like you are using `readline` not `readlines`, readline reads a single line. — Padraic Cunningham, Mar 09 '15 at 21:42

score 1 · Answer 1 · edited Mar 09 '15 at 21:26

1

This will put the each line into separate sub lists in a 2d list:

sav = []
with open("filename", "r") as fileopen:
    for line in fileopen:
        sav.append(line.split())

I'm assuming you are using a .txt file.

edited Mar 09 '15 at 21:26

Will

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answered Mar 09 '15 at 21:23

zeldor

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What does the r in open do? – Andrew3943 Mar 09 '15 at 21:55
`r` is used to read the file, `w` to write to it and `a` to append to it. There are more of these, but they will be easy to find on the internet. – zeldor Mar 09 '15 at 21:59
So if I am understanding this correctly it opens the file then it reads every line then it appends them to list sav am I close? – Andrew3943 Mar 09 '15 at 22:01
Yes - it puts them into a 2d list. – zeldor Mar 10 '15 at 18:42

score 0 · Answer 2 · answered Mar 09 '15 at 22:59

This is basically going to make an sequence named 'tup'. What open() does is open up the file. The two arguments that you pass will be the 'filename' and the what you want to do with the contents of the file. Filename is going to be the entire directory of the file, i.e "C:/User...../file.txt". What 'r' signify is 'read' a file only. tuple() will create a sequence of data from your file which will be immutable (you cannot change it), but you can access the data within it.

    tup=tuple(open(file,'r'))

I found a similar question from a while ago, this might help also. http://stackoverflow.com/questions/3277503/python-read-file-line-by-line-into-array — Rogue, Mar 09 '15 at 23:07

Python opening a file and turning it into a list

2 Answers2